1. Field of the Invention
The present invention relates to a system for detecting the presence of a user especially at the level of a motor vehicle opening panel.
The invention relates more particularly to a user presence detection system incorporating a presence sensor having means for locally creating a zone of nondetection of presence.
The invention also pertains to a system for locking and/or unlocking at least one opening panel of a motor vehicle incorporating such a user presence detection system.
2. Description of Related Art
In the automobile sector, the opening panel handle which over time served only to transmit a mechanical movement by way of a linkage to a lock for opening the opening panel has evolved greatly.
Specifically, in particular in respect of so-called “hands free” access systems allowing the locking and the unlocking of a motor vehicle without mechanical key or remote control, the handle has become a privileged interface between the user carrying an identifier (for example in the form of a tag) and the system on board the vehicle.
With these hands-free access systems, it has become necessary to define novel access systems and in particular novel systems allowing the detection of a user wishing to access his vehicle, this detection of presence of the user making it possible thereafter to initiate his identification with a view to authorizing his access to the vehicle.
A handle used in a hands-free access system is represented in FIG. 1. Generally, such a handle 1 is carried by an opening panel O of a motor vehicle V and is composed of two parts, a gripping part 2 moveable with respect to the opening panel O and a part 3 fixed on the bodywork of the opening panel O. This fixed part is essentially decorative and incorporates, for example, an emergency lock.
Document DE-A-196 17 038 describes a presence detection system, positioned at the level of a motor vehicle opening panel equipped with a hands-free access system, for detecting the approach of a user at the level of the handle of the opening panel. The presence detection system comprises a presence sensor comprising an electronic monitoring module, a first electrode disposed in the gripping part of the handle and a second electrode disposed at the level of the opening panel.
The electromagnetic coupling which is established between the two electrodes generates a user presence detection zone at the level of the handle. Thus, when the user approaches the handle with his hand with a view to accessing his vehicle, his presence is detected and his identification, by communication between the vehicle and the identifier carried by the user, is initiated.
However, when the two electrodes of the user presence sensor are both positioned at least in part at the level of the handle, the presence detection zone may be very extensive and in particular encompass zones in which no detection is desired. For example and as represented in FIG. 1, for reasons of ergonomics of use, it is desirable to have maximum detection at the level of the gripping part 2 of the handle and minimum detection, or even zero detection, at the level of certain zones of the fixed part 3 of the handle positioned on the bodywork of the opening panel.
Moreover, in certain devices, the presence detection sensor is incorporated into a reduced space especially at the level of the handle, and the user presence detection zone associated therewith may be very extensive and in particular encompass the electronic module of the sensor. This arrangement generates, at the level of the electronic module, electromagnetic disturbances that may seriously impede the operation of the presence detection sensor.